How to Choose the Right Battery for Your Car
Whether you bought your car pre-owned or fresh off the line, it likely came standard with a battery on board. But given that the average vehicle battery lasts about three to five years before it needs to be replaced, chances are you will need to select a new battery at some point in the life of your car.
Your trusted mechanic can help you with this process. Still, it’s useful to have a basic understanding of the different types of batteries available today and which one is the best fit for your vehicle and driving style.
Consider this your guide to all things vehicle batteries.
A Brief History of Car Batteries
Lead-acid battery technology has been around since 1859, when French physicist Gaston Planté developed the first lead-acid battery. But the battery vehicle connection wouldn’t be made for another half-century. In the earliest days of motor vehicles, there were no electrical components in cars and, therefore, no need for a battery. That all changed by 1920 as cars began to come equipped with starting motors.
Battery fact: Hudson Motor Car Company was the first to use a standard battery size per Battery Council International (BCI) specifications. BCI group sizes are still used today.
Understanding Different Types of Car Battery Types
Today, drivers have a number of options for vehicle batteries.
Flooded Lead-Acid Batteries
Also known as flooded lead-acid (FLA) or wet cell batteries, conventional lead-acid batteries are still popular in gas-powered cars, trucks and vans.
Inside a standard FLA, you’ll find positive and negative lead plates submerged in a solution of sulfuric acid and water, known as the electrolyte.
When you turn the ignition key, a chemical reaction occurs between the lead plates and the electrolyte. This reaction generates electrons, producing electrical energy that flows through the terminals and powers the starter motor. The starter motor then cranks the engine, allowing it to draw in air and fuel to begin the combustion process. Once the engine is running, the alternator takes over to power the electrical systems and recharge the battery for the next start.
Advantages of FLAs:
- Cost. FLAs are relatively inexpensive compared to other types of vehicle batteries.
- Availability. If your car dies, it’s typically not hard to find a lead-acid car battery quickly.
Drawbacks of FLAs:
- Lifespan. FLAs last about three to five years on average. This is less than some of the newer technologies we’ll discuss below.
- Not maintenance-free. FLAs may require filling and can spill if jostled or turned.
Common applications for conventional lead-acid batteries include standard and older-model vehicles and those with fewer electrical requirements (think just headlights and a radio).
Absorbed Glass Mat (AGM) Batteries
AGMs are a type of lead-acid battery, but instead of a liquid electrolyte, the sulphuric acid solution is trapped in fiberglass mats that sit snugly between the lead plates. AGMs are fully sealed, and because the electrolyte is suspended in the mats, there is no risk of leakage.
FLAs still make up the majority of vehicle batteries in cars and trucks today, but AGMs are on the rise. That’s because today’s cars tend to have significantly more electrical needs than older model vehicles. With everything from heated seats and Bluetooth speakers to stop-start technology and parking assist, your car is drawing more electrical power than ever.
AGMs rise to the electrical demand challenge because of their lower internal resistance — about 2% compared to 10%-15% in FLA batteries — which means higher power output and faster charging.
Advantages of AGM batteries
- Tough. Lower internal resistance and higher power output mean quicker charging time. They are also better at resisting vibration than FLAs.
- Maintenance free. They are non-spillable and sealed, meaning they don’t need to be watered.
- Longer lifespan. AGMs can last twice as long as an FLA. Typically, they will produce about 60,000 engine starts, which is three times more than FLAs.
Drawbacks of AGMs
- Cost. AGMs can cost between 40% and 100% more than a comparable FLA.
- Compatibility. Not all vehicles are designed to accept AGM batteries. Make sure to check with your manual and mechanic before installing.
AGMs are ideal for vehicles with high electrical demands, such as modern cars equipped with advanced features like stop-start systems, infotainment centers, heated seats and safety technologies. They’re also a great fit for vehicles frequently driven in start-stop traffic.
Enhanced Flooded Batteries (EFB)
As the name suggests, EFBs are an enhanced version of conventional flooded lead acid batteries. They are designed to handle the increased power demands of modern cars (like stop-start technology) but cost less than AGMs. EFBs are wet cell batteries, but the lead plates are thicker and lined with a poly fleece material, enabling a more consistent energy flow and the ability to handle frequent charging and discharging cycles better than FLAs.
Advantages of EFBs:
- Cost-effective. EFBs split the difference between AGMs and FLAs in performance and cost.
- Longer lasting. EFBs last up to six years and about 1,000 cycles.
Drawbacks of EFB Batteries
- Limited deep discharge. EFBs can handle more discharges than FLAs but are not as robust as AGMs.
- Moderate lifespan. While EFBs outperform FLAs in cycle life, they still fall short of the longevity offered by AGMs.
EFBs are best for small- to mid-range vehicles with stop-start technology or hybrid systems.
Lithium-ion batteries (Li-ion)
Li-ion batteries are the new kids on the battery block. While lead-acid technology has been around for over 150 years, the first lithium-ion battery prototype arrived in 1985. Li-ion batteries use lithium compounds as their primary component, allowing for a much lighter, more energy-dense power source that delivers superior performance and efficiency.
Li-ion batteries are the go-to choice for electric vehicles (EVs) and plug-in hybrids. They are also increasingly showing up in performance and luxury cars.
Advantages of Lithium-Ion Batteries
- High energy density. Li-ion batteries can store more energy in a smaller, lighter package than lead-acid batteries.
- Longer lifespan. Li-ion batteries have a significantly longer lifespan than even the most advanced lead-acid batteries, up to 10,000 cycles.
- Maintenance-free. Li-ions are completely sealed and maintenance-free.
Drawbacks of Lithium-Ion Batteries
- Cost. Li-ions are significantly more expensive upfront than their lead-acid counterparts.
- Temperature sensitivity. Li-ion batteries have extreme temperatures, which can impact performance and longevity if not properly managed.
- Not interchangeable. Traditional gas-powered cars, especially older models, may not be able to support li-ion batteries. Consult with your manual and qualified technician before deciding on lithium.
Factors to Consider When Choosing a Battery
The first thing to consider when selecting a replacement battery for your vehicle is whether it is compatible with your car. Consult your manual and ask your mechanic for recommendations on the best type of battery.
If your car will support an upgrade from an FLA to AGM or EFB, consider the cost vs. benefit of making the switch. AGM will cost more up front, but will likely last longer. If your car is tricked out with aftermarket electronics, a more robust battery may be the way to go.
Whichever option you choose, ultimately the health of your battery is directly related to your general driving habits and maintenance. The following best practices can help to extend the life of your battery, regardless of the type:
- Drive regularly. Batteries recharge as you drive. Limit frequent short trips and long periods where your car (and battery) are sitting idle. If you store your car over the winter, disconnect the battery and hook it up to a trickle charger to prevent drain.
- Watch out for parasitic draw. The electronics in your car will continue to draw energy from the battery even when your car is off. Be mindful of accessories or devices that could drain the battery over time if not properly managed. Consult a mechanic if your battery seems to be draining more quickly than usual.
- Keep it clean. If you have an FLA battery, make sure to periodically check for corrosion on the terminals and connection points. If you notice corrosion (a green or white powdery substance), clean with baking soda and water.
- Test and maintain. Make sure to keep up on your maintenance schedule, which should include battery testing and maintenance.
If you have any questions or concerns about your battery, or simply need advice on what to choose for your next replacement, give us a call or stop by your nearest Boyce Auto location.
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